Biotinidase deficiency--clinching the diagnosis rapidly can make all the difference!

A 2-month-old male infant, born of second degree consanguineous parentage, presented with seizures not responding to phenytoin and phenobarbitone. His perinatal period had been uneventful and there was no family history of seizures. On examination, he had failure to thrive, perioral and perianal rash, alopecia with hypopigmented hair, seborrhoeic dermatitis, bilateral blepharitis, respiratory distress and stridor. Neurological examination revealed hypertonia of all the four limbs, exaggerated deep tendon reflexes and papilloedema. Biotinidase deficiency was suspected within 24 h of admission and empiric oral biotin 10 mg twice daily was started. The symptoms, especially seizures, dramatically improved within 48 h. Serum biotinidase levels revealed a profound deficiency (0.10 nmol/min/ml serum) and the parents were advised regarding the need for regular biotin supplementation. The child is presently 10 months old, thriving well, developmentally normal and is seizure free with total resolution of skin and hair lesions.